[K12OSN] Server Sizing for 150 Users

[info <linux cotmac-proex com>]

Hello,
I want to use a X-server for following applications , what should be the 
ideal server sizing for the 150 nos of thin-client
1) ICEwm
2) Netscape 7.0 for specific application
3) Firefox 2.0
4) Open-office 2.3
5) Mail-client Sylpheed
Which RAID configuration i should use.

I am planning a Xeon Dual processor server with 4 GB of RAM,

Regards
K.Dinesh